Golf putter with range of feel characteristics

ABSTRACT

A golf putter head includes a back body and a face body having a golf ball contact surface. The face body includes an entirety of the contact surface, with the back body and the face body having surfaces without contact across a gap defined by the surfaces. The golf putter head further includes a vibration dampening intermediate body filling the gap to isolate the face body from the back body by completely separating the back body and the face body from one another. The intermediate body has a durometer selectable during assembly of any number within a range of 40 to 90 Shore-A. A coefficient of restitution of the golf ball contact surface of the golf putter head has a direct relationship with the durometer of the intermediate body such that golf putter heads with varying coefficients of restitution may be fabricated by varying the durometer of the intermediate body.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims priority under 35 U.S.C. §119(e) to U.S. Provisional Application Ser. No. 62/331,541 entitled “GOLF PUTTER WITH RANGE OF FEEL CHARACTERISTICS,” filed on May 4, 2016, which is incorporated herein by reference in its entirety.

BACKGROUND OF THE DISCLOSURE

The present disclosure relates to golfing equipment, and more particularly to golf putters. A golf putter is a club used in golf to move the golf ball very short distances, typically on a putting green. The act of putting requires the player to precisely strike the golf ball along the putting green into a golf hole. Designs of golf putters are directed to improving the smoothness of the stroke, the glide of the golf putter along the putting surface, the ability to achieve solid impact when striking the golf ball, and reducing bounce when striking the golf ball to encourage topspin during the roll of the golf ball. Most golf putters include an elongate shaft and a head with a striking surface having a two to four degrees of loft. The shaft includes a grip that does not have to be round, but can include a flat top and curved underside.

Examples of golf putters can be found in U.S. Pat. No. 5,458,332 to Fisher, U.S. Pat. No. 5,674,132 to Fisher, U.S. Pat. No. 5,921,871 to Fisher, U.S. Pat. No. 7,112,147 to Solheim et al., U.S. Pat. No. 7,374,499 to Jones et al., U.S. Pat. No. 7,641,569 to Best et al., U.S. Pat. No. 8,747,245 to Franklin et al., U.S. Pat. No. 8,900,071 to Kii, U.S. Pat. No. 8,979,668 to Nakamura, and U.S. Pat. No. 9,072,948 to Franklin et al., to name a few.

Reference also can be made to U.S. Pat. No. 8,523,698 to Hotaling et al., entitled GOLF PUTTER, which is owned by the assignee of this disclosure and discloses embodiments of a golf putter having such an insert to dampen vibration.

USGA Equipment Rules Appendix II 5a requires that the face of a putter “must have a hardness of no less than 85 on a shore-A scale durometer”. Roughly equivalent to 25-30 Shore-D, this requirement renders older examples of prior art with softer faces (e.g., the three Fisher patents) non-conforming. More recent examples of prior art where durometer is specified place a minimum value no less than 25 Shore-D for this reason, as some portion of their dampening material extends to the face (i.e., U.S. Pat. No. 8,979,668 to Nakamura, U.S. Pat. No. 8,900,071 to Kii, U.S. Pat. No. 8,747,245 to Franklin et al. and U.S. Pat. No. 7,374,499 to Jones et al.). Still other prior art examples of golf putters do not specify durometer at all when describing the dampening material (e.g., U.S. Pat. No. 8,523,698 Hotaling et al.; U.S. Pat. No. 7,641,569 Best et al.).

SUMMARY OF THE DISCLOSURE

One aspect of the disclosure is directed to a golf putter head including a back body adapted to be secured to a golf club shaft, and a face body including a golf ball contact surface. The face body includes an entirety of the contact surface, with the back body and the face body having surfaces without contact across a gap defined by the surfaces. The golf putter head further includes a vibration dampening intermediate body filling the gap to isolate the face body from the back body by completely separating the back body and the face body from one another. The intermediate body is affixed to the back body and the face body. The intermediate body has a durometer selectable during assembly of any number within a range of 40 to 90 Shore-A. The arrangement is such that a coefficient of restitution of the golf ball contact surface of the golf putter head is in a direct relationship with the durometer of the intermediate body such that golf putter heads with varying coefficients of restitution may be fabricated by varying the durometer of the intermediate body.

Embodiments of the golf putter head further may include the coefficient of restitution of the putter head measured using a static drop method is in a range from 0.75 to 0.95. The coefficient of restitution of the putter head measured using a static drop method is less than 0.75. The intermediate body may not extend to the face of the golf putter head. The outermost perimeter of the face body may define an outermost perimeter of the golf putter head. The front surface of the face body may include only a portion of the front surface of the golf putter head. The intermediate body may have a durometer of 50 to 60 Shore-A. The intermediate body may have a durometer of 70 Shore-A. The intermediate body may have a durometer of 90 Shore-A. The intermediate body can be selected from one of several durometers. The intermediate body options include durometers of 50 to 60, 70 and 90 Shore-A. The intermediate body may include a first surface and a second, opposing surface. At least one of the first surface and the second surface may include a series of ridges, grooves, or indentations formed on the surface.

BRIEF DESCRIPTION OF THE DRAWINGS

Various aspects of at least one embodiment are discussed below with reference to the accompanying figures, which are not intended to be drawn to scale. Where technical features in the figures, detailed description or any claim are followed by references signs, the reference signs have been included for the sole purpose of increasing the intelligibility of the figures, detailed description, and claims. Accordingly, neither the reference signs nor their absence are intended to have any limiting effect on the scope of any claim elements. In the figures, each identical or nearly identical component that is illustrated in various figures is represented by a like numeral. For purposes of clarity, not every component may be labeled in every figure. The figures are provided for the purposes of illustration and explanation and are not intended as a definition of the limits of the invention. In the figures:

FIG. 1 is a composite of photographs taken during static drop tests conducted to measure the COR values of various putter constructions;

FIG. 2 is a perspective view of an assembled putter head of an embodiment of the present disclosure;

FIG. 3 is a cross-sectional view of the putter head shown in FIG. 2;

FIG. 4 is an exploded cross-sectional view of the putter head, showing a back body, an intermediate body, and face body of the putter head separated as pre-assembled parts; and

FIGS. 5-7 are perspective views of a putter head of another embodiment of the present disclosure.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Embodiments of the present disclosure are directed to a golf club, and more particularly a golf putter head. The golf putter head is designed to be secured to a shaft, which is elongate in construction, typically 32- to 35-inches in length, but may also be longer. In the shown embodiments, the golf putter head includes an opening for receiving the shaft therein in a secure manner. For example, belly putters and long putters may be up to 48-inches in length. In one embodiment, the shaft is a tapered tube made of metal (usually steel) or carbon fiber composite (referred to as graphite). The shaft is roughly 0.5 to 1.0 inches in diameter near the grip. The shaft of the golf putter can weigh from 1.6 to 5.3 ounces, depending on the material and length of the shaft. The shaft includes a grip provided at an upper end of the shaft. The grip enables the golfer to easily grip and manipulate the golf putter when putting. The grip of the golf putter can have a circular cross-section, but may also include any cross section that is symmetrical along the length of the grip through at least one plane.

The golf putter head is attached to a lower end of the shaft and configured to strike a golf ball (not shown). The golf putter head further may include a hosel that is designed to connect the head to the shaft. In some embodiments, the hosel may be provided separately from the head or be integrally formed with the head. The hosel may be optimized to place as little mass as possible over the top of the golf putter head to lower the center of gravity of the golf putter head. In certain embodiments described herein, the golf putter head includes a back body and a face body. In some embodiments, the back body and the face body may be die cast, machined, forged or otherwise manufactured from the same or different materials. Such materials may include any suitable metal or alloy. Suitable non-metallic materials may include wood, ceramic, glass, stone, and the like.

In certain embodiments, the golf putter head further includes a vibration dampening intermediate body, which is provided to fill a gap between a surface forming an opening of the metal back body and an outer surface of the metal face body to isolate the metal back body from the metal face body. In one embodiment, the vibration dampening intermediate body includes a polymeric material. Particularly, the polymeric material may include at least one material selected from the group of following materials: urethane, thermoplastic elastomer (TPE) polyester, silicone, rubber, polypropylene, polyethylene, polycarbonate, acrylonitrile-butadien-styrene (ABS), polyvinyl chloride (PVC), nylon, acrylic, acetal, and the like. The result is that the face body is joined to the back body. The vibration dampening intermediate body acts as a vibration dampening device in addition to mechanically joining the two face and back bodies together. The golf putter head is assembled by placing the back body and the face body in a mold (not shown) designed to ensure the gap is provided between the respective bodies, into which a liquid polymer (or other suitable material) is poured or otherwise injected to substantially fill the gap. Once the polymer is set, the golf putter head is removed from the mold where it can be attached to the shaft.

Embodiments of the present disclosure are directed to a head of a golf putter comprised of a back body configured to be secured to a shaft, a face body including a golf ball contact surface, a gap between the back body and face body defined by at least partially non-planar opposing surfaces, and an intermediate body filling the gap to isolate the face body from the back body. The intermediate body does not extend to the contact surface and includes a durometer between approximately 40 Shore-A and at least 90 Shore-A, in which putter heads may be produced with intermediate bodies of different durometers to provide a range of feel options to the golfer.

The face and back bodies are made of a high-density material, preferentially metallic, while the intermediate body is preferably fabricated from a polymer, for instance TPE or urethane. The intermediate body may be completely internal and therefore hidden, or it may visibly extend to any surface of the putter head (sole, crown, heel, toe, or back) except for the face, as in the preferred embodiment.

In the preferred embodiment the dampening member does not extend to the contact surface and therefore much softer durometers (as low as approximately 40-50 Shore-A) are possible while still conforming to the rules of golf. This is advantageous as it allows for the creation of a range of putters with distinct “feel levels” easily discernible by golfers. Said putters could be geometrically identical, differing only in the durometers of their respective intermediate bodies. This not only improves manufacturing efficiencies but also enables golfers and professional fitters to select by feel preference separate from other factors such as head shape.

It is possible to quantify “feel” as the amount of energy imparted to the ball at impact measured as the coefficient of restitution (COR) using the static rebound method (FIG. 1). COR values are common with other types of golf equipment, such as drivers, and are a measure of a surface's “bounciness”, e.g. how much energy is reflected versus absorbed by a surface. The COR value of a putter correlates to how far a ball will roll with a given stroke. Since every golfer has an innate sense of how far the ball should roll, matching this sense to a putter with the correct COR value is imperative for improving distance control and therefore accuracy.

To obtain the COR measurements shown in Table 1, a 2015 Titleist® Pro V1® golf ball was dropped from 32 inches above the face of the putter, which was affixed to a concrete floor facing upwards. The subsequent rebound height was captured with high-speed photography. As the rebound percentage depends on the object dropped, it is important to note that these COR values illustrate a relative difference between the putters tested, not an absolute value.

The range of durometers from about 40 to 90 Shore-A in the preferred embodiment provides a range of putter COR values in between that of a typical insert-faced putter on the low end and a solid body, non-insert putter on the high end (Table 1). This allows for a range of fitting options not previously possible with existing technologies. Along with the durometer of the intermediate body, the relatively substantial mass of the face body contributes to this effect. The high COR value of the large metal face body mitigates the dampening effect of the polymer, yielding a combined COR value higher than would be possible from a typical polymer face insert. In the preferred embodiment, the mass of the face body (˜100 grams) would be approximately twice that of a golf ball (46 grams).

Because the face body is completely isolated e.g. “floating” by virtue of the polymer intermediate body from the rest of the putter (including the shaft and grip), changes in durometer of the polymer have a significant impact on the putter's COR value and subsequent feel. In contrast, some examples in the art (exemplified by U.S. Pat. No. 9,072,948 Franklin) use a polymer layer to separate a front portion, which includes the face, hosel, shaft and grip, from a rear “weight bearing” section in order to dampen impact vibrations. As there is a direct solid connection between the striking face and the grip, changing the durometer of the polymer layer does not affect the feel as effectively as it does with embodiments of the golf putter of the present disclosure.

In the preferred embodiment the face body and back body are isolated from each other by the intermediate body so that there is no direct contact between the two bodies, whereas the face body constitutes the entire front striking face of the putter body and the intermediate body does not extend to the front face. This configuration is optimal for allowing the face to “float” so that its rebound dynamics are affected by the durometer of the intermediate body independent of the back body. This also allows for the widest range of durometers possible for the intermediate body while adhering to the USGA rules for equipment.

Alternately, the face body may constitute only a portion of the front-facing surface of the putter head. As such, the face body may be configured as an insert within the front surface of the back body.

The intermediate body may be introduced as a liquid (through casting or injection-molding processes) between the face and rear bodies, permanently bonding them together. Alternately, intermediate bodies of differing durometers may be molded separate from the other parts and then assembled together with the other parts with adhesive, pressure, etc.

FIG. 1 is a composite of photographs taken during static drop tests conducted to measure the COR values of various putter constructions. From the left they are: a typical polymer insert-face putter; a design of the preferred embodiment of the disclosure with a 60 Shore-A durometer intermediate body; the same with a 70 Shore-A durometer intermediate body; the same with a 90 Shore-A intermediate body; and a solid-body, non-insert putter. The lines show the average maximum rebound height for the two extremes.

TABLE 1 60 Shore-A 70 Shore-A 90 Shore-A 90 Shore-A Intermediate Intermediate Intermediate Solid Insert-Face Body Body Body Body average rebound (inches) 21.25 22.71 22.97 23.34 24.45 % rebound (32″ drop height) 66.41% 70.96% 71.78% 72.95% 76.42% COR value 0.815 0.842 0.847 0.854 0.874

FIGS. 2-4 illustrate an assembled golf putter head of the preferred embodiment, generally indicated at 200. As shown, the golf putter head 200 includes a back body 210 adapted to be secured to a golf club shaft 220 and a face body 230 including a golf ball contact surface 240. The face body 230 includes an entirety of the contact surface 240. The back body 210 and the face body 230 have surfaces without contact across a gap 250 defined by the surfaces. The golf putter head 200 further includes a vibration dampening intermediate body 260 filling the gap to isolate the face body 230 from the back body 210 by completely separating the back body and the face body from one another. The intermediate body 260 is affixed to the back body 210 and the face body 230. In one embodiment, the intermediate body 260 has a durometer selectable during assembly of any number within a range of 40 to 90 Shore-A. In one embodiment, one of three different polymer formulations is used when molding the putter head 200, with each formulation having a different durometer and color.

As mentioned above, the coefficient of restitution (COR) is the ratio of the final to initial velocity difference between two objects after they collide. The COR ranges from 0 to 1, in which 1 is a perfectly elastic collision. The COR is nearly always less than 1 due to initial translational kinetic energy lost to rotational kinetic energy, heat, and deformation. With the golf putter head 200 of the present disclosure, the coefficient of restitution of the golf ball contact surface 240 of the golf putter head is in a direct relationship with the durometer of the intermediate body 260, such that golf putter heads with varying coefficients of restitution may be fabricated by varying the durometer of the intermediate body.

FIG. 3 illustrates a cross-sectional view of the putter head 200. As shown, the face body 230 comprises the entire ball contact surface 240. The surfaces that define the gap 260 may have steps, grooves, channels, etc. to aid in adhesion of the intermediate body as shown, or for other advantageous effect.

FIG. 4 illustrates an exploded cross-sectional view of the golf putter head 200 showing the back body 210, intermediate body 260, and face body 230 separated as pre-assembled parts. The intermediate body 260 is fabricated using materials of different durometer (260A, 260B, and 260C) to create putter heads with different COR values and feel. In this example, option A, e.g., intermediate body 260A, is a soft durometer (50 Shore-A), option B, intermediate body 260B, is medium (70 Shore-A), and option C, e.g., intermediate body 260C, is firm (90 Shore-A). In practice any number of options can be made of any durometer within the acceptable range.

For example, the intermediate body can be provided from one of three, separate intermediate bodies, e.g., 260A, 260B, and 260C. Specifically, in a certain embodiment, the intermediate body, e.g., intermediate body 260A, has a durometer of 50 to 60 Shore-A. In another embodiment, the intermediate body, e.g., intermediate body 260B, has a durometer of 70 Shore-A. In another embodiment, the intermediate body, e.g., intermediate body 260C, has a durometer of 90 Shore-A. The intermediate body can be selected from one of several durometers, including durometers of 50 to 60, 70 and 90 Shore-A.

In one embodiment, the coefficient of restitution of the putter head measured using a static drop method is in a range from 0.75 to 0.95.

In one embodiment, the coefficient of restitution of the putter head measured using a static drop method is less than 0.75.

In one embodiment, the intermediate body does not extend to the face of the golf putter head.

In one embodiment, the outermost perimeter of the face body defines an outermost perimeter of the golf putter head.

In one embodiment, the front surface of the face body comprises only a portion of the front surface of the golf putter head.

In one embodiment, the intermediate body includes a first surface and a second, opposing surface.

In one embodiment, at least one of the first surface and the second surface includes a series of ridges, grooves, or indentations formed on the surface.

FIGS. 5-7 illustrate a golf putter head, generally indicated at 500, of another embodiment of the present disclosure.

Also, the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. Any references to embodiments or elements or acts of the systems and methods herein referred to in the singular may also embrace embodiments including a plurality of these elements, and any references in plural to any embodiment or element or act herein may also embrace embodiments including only a single element. References in the singular or plural form are not intended to limit the presently disclosed systems or methods, their components, acts, or elements. The use herein of “including,” “comprising,” “having,” “containing,” “involving,” and variations thereof is meant to encompass the items listed thereafter and equivalents thereof as well as additional items. References to “or” may be construed as inclusive so that any terms described using “or” may indicate any of a single, more than one, and all of the described terms. Any references to front and back, left and right, top and bottom, upper and lower, and vertical and horizontal are intended for convenience of description, not to limit the present systems and methods or their components to any one positional or spatial orientation.

Having thus described at least one embodiment of the present disclosure, various alternations, modifications and improvements will readily occur to those skilled in the art. Such alterations, modifications and improvements are intended to be within the scope and spirit of the disclosure. Accordingly, the foregoing description is by way of example only and is not intended to be limiting. The disclosure's limit is defined only in the following claims and equivalents thereto.

For example, although most golf putters have a 32-inch to a 35-inch shaft (slightly shorter for most ladies and juniors, longer for most men), golf putters are also made with longer shaft lengths and grips, and are designed to reduce the number of moving parts during the putting motion. One example is a belly putter, which is typically about six to eight inches longer than a normal putter and is designed to be anchored against the stomach of the player. This design reduces or removes the importance of the hands, wrists, elbows, and shoulders and thus reduces the number of moving parts while putting. Another example is a long putter, which is even longer than a belly putter and is designed to be anchored from the chest or even the chin and similarly reduces the impact of the hands, wrists, elbows and shoulders. The principles disclosed herein with reference to golf putters may be applied to belly putters and long putters.

As putting is one of the most important aspects of a player's golf game, a variety of teaching tools are available to assist the player in learning correct putting technique. The principles disclosed herein also may be applied to teaching tools, such as training clubs designed to teach the golfer to use a steady, even putting motion without any sudden pressure applied by the hands or arms to swing the club or to hit a straight shot. 

What is claimed is:
 1. A golf putter head comprising: a back body adapted to be secured to a golf club shaft; a face body including a golf ball contact surface, the face body including an entirety of the contact surface, the back body and the face body having surfaces without contact across a gap defined by the surfaces; and a vibration dampening intermediate body filling the gap to isolate the face body from the back body by completely separating the back body and the face body from one another, the intermediate body being affixed to the back body and the face body, the intermediate body having a durometer selectable during assembly of any number within a range of 40 to 90 Shore-A, a coefficient of restitution of the golf ball contact surface of the golf putter head being in a direct relationship with the durometer of the intermediate body such that golf putter heads with varying coefficients of restitution may be fabricated by varying the durometer of the intermediate body.
 2. The golf putter head of claim 1, wherein the coefficient of restitution of the putter head measured using a static drop method is in a range from 0.75 to 0.95.
 3. The golf putter head of claim 1, wherein the coefficient of restitution of the putter head measured using a static drop method is less than 0.75.
 4. The golf putter head of claim 1, wherein the intermediate body does not extend to the face of the golf putter head.
 5. The golf putter head of claim 1, wherein the outermost perimeter of the face body defines an outermost perimeter of the golf putter head.
 6. The golf putter head of claim 1, wherein the front surface of the face body comprises only a portion of the front surface of the golf putter head.
 7. The golf putter head of claim 1, wherein the intermediate body has a durometer of 50 to 60 Shore-A.
 8. The golf putter head of claim 1, wherein the intermediate body has a durometer of 70 Shore-A.
 9. The golf putter head of claim 1, wherein the intermediate body has a durometer of 90 Shore-A.
 10. The golf putter head of claim 1, wherein the intermediate body can be selected from one of several durometers.
 11. The golf putter head of claim 1, wherein the intermediate body options include durometers of 50 to 60, 70 and 90 Shore-A.
 12. The golf putter head of claim 1, wherein the intermediate body includes a first surface and a second, opposing surface.
 13. The golf putter head of claim 12, wherein at least one of the first surface and the second surface includes a series of ridges, grooves, or indentations formed on the surface. 